They use

to tell what characters do or think and to provide information about lighting, scenery, and other effects.

As an AI language model, I can tell you that the word missing in your sentence is "stage directions". Stage directions are written instructions in a script that guide actors, directors, and other production members on how to perform a play or theatrical piece. They give details about the physical actions, movements, and expressions of the characters, as well as provide information about the environment, set design, lighting, sound, and any other potential effects required for the performance. Stage directions help bring the written words to life on stage and enhance the overall production.